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Advancing Thailand’s aquaculture industry through Aqua-RASD

Aqua-RASD is a closed recirculating aquaculture system integrated with the hybrid nitrification biofilter tanks for ammonia removal and patented Tubular Denitrification Reactor (TDNR) for nitrate removal. The system can be applied to aquaculture ponds, both seawater and freshwater, for cultivating economic aquatic animal. The technology was developed by Dr. Sorawit Powthongsook, BIOTEC researcher, based at Center of Excellence for Marine Biotechnology.

In general, decomposition of organic matters in the pond produces toxic inorganic nitrogen compounds such as ammonia and nitrite. These nitrogen compounds are usually removed by water exchange. To minimize the water exchange, ammonia and nitrite must be treated by nitrification process, whereby ammonia and nitrite are converted to nitrate which has low toxicity. With this process, water exchange can be prolonged to several weeks until nitrate concentration is accumulated to higher than 50 mg-N/L. To prolong water exchange, nitrate can be treated by denitrification process. Though denitrification is common in urban and industrial wastewater treatment, the use of denitrification in aquaculture systems is still limited due to the complexity of anoxic reactor and problems from incomplete denitrification process such as nitrite accumulation and sulfate reduction to hydrogen sulfide which could seriously harm to the cultured animals. Research team at the Center of Excellence for Marine Biotechnology, therefore,designed a tubular denitrification reactor (TDNR) which can overcome the limitations of denitrification column.

Aqua-RASDis a promising and eco-friendly technology for the sustainable aquaculture.Equipped with the hybrid nitrification biofilter tanks and patented Tubular Denitrification Reactor (TDNR), the system can completely remove nitrogen compounds, in the forms of ammonia, nitrite and nitrate. Thus, water can be recirculated efficiently within the system leading to the cutback of water exchange from 15-20% per day to 0.5% per day. In addition, this technology can prolong water exchange for a year or more as well as reduce the expenses of chemical preparation, seawater transportation and also prevent aquatic animal farming from infectious diseases transmitted in the water.

Aqua-RASD has already been licensed to several aquatic companies with different applications. Aquatica Co., Ltd., an operator of aquarium retailer and aquarium setting services, uses the system in a large aquarium. Sea Born Co., Ltd. has the system installed in an intensive fish breeding tank.

Aqua-RASDhas recently been installed at the new R&D Center for Aquaculture Feed of Thai Luxe Enterprises, which had an opening on 25 October 2013.